CVE-2024-21647: puma Request Smuggling — Fix

Description

Puma is a web server for Ruby/Rack applications built for parallelism. Prior to version 6.4.2, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies in a way that allowed HTTP request smuggling. Fixed versions limits the size of chunk extensions. Without this limit, an attacker could cause unbounded resource (CPU, network bandwidth) consumption. This vulnerability has been fixed in versions 6.4.2 and 5.6.8.

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CVSS v3.1 Score

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-444 CWE-444

Affected Products

Vendor	Product	Versions
puma	puma	< 5.6.8
puma	puma	6.0.0 — 6.4.2

References

Advisories & Patches

https://github.com/puma/puma/commit/5fc43d73b6ff193325e657a24ed76dec79133e93 https://github.com/puma/puma/security/advisories/GHSA-c2f4-cvqm-65w2 https://github.com/puma/puma/commit/5fc43d73b6ff193325e657a24ed76dec79133e93 https://github.com/puma/puma/security/advisories/GHSA-c2f4-cvqm-65w2

Other References

https://lists.debian.org/debian-lts-announce/2024/11/msg00004.html

Frequently Asked Questions

What is CVE-2024-21647? +

Puma is a web server for Ruby/Rack applications built for parallelism. Prior to version 6.4.2, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies in a way that allowed HTTP request smuggling. Fixed versions limits the size of chunk extensions. Without this limit, an attacker could cause unbounded resource (CPU, network bandwidth) consumption. This vulnerability has been fixed in versions 6.4.2 and 5.6.8. It has a CVSS v3.1 base score of 5.9 (MEDIUM).

How severe is CVE-2024-21647? +

CVE-2024-21647 has a CVSS v3.1 score of 5.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-21647? +

CVE-2024-21647 affects products from puma, specifically: puma. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-21647? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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